1,651 research outputs found
CCS Networks for the UK: Benefits, Impacts and Regulation
What benefits might be offered by developing well planned CCS networks? A review of the drivers for and barriers to the coherent development of CCS networks in the UK is used to synthesise a limited set of possible network topologies. The benefits offered by each topology for UK carbon dioxide and other atmospheric emissions are estimated. Other potential benefits are considered qualitatively, and a range of uncertainties identified. The complexity of CCS networks means that addressing these uncertainties is a challenging task, and the need for a whole systems approach is evaluated. Finally, implications for CCS regulation and policy are highlighted
Deformations of the Boson Representation and its Subalgebras
The boson representation of the sp(4,R) algebra and two distinct deformations
of it, are considered, as well as the compact and noncompact subalgebras of
each. The initial as well as the deformed representations act in the same Fock
space.
One of the deformed representation is based on the standard q-deformation of
the boson creation and annihilation operators. The subalgebras of sp(4,R)
(compact u(2) and three representations of the noncompact u(1,1) are also
deformed and are contained in this deformed algebra. They are reducible in the
action spaces of sp(4,R) and decompose into irreducible representations.
The other deformed representation, is realized by means of a transformation
of the q-deformed bosons into q-tensors (spinor-like) with respect to the
standard deformed su(2). All of its generators are deformed and have
expressions in terms of tensor products of spinor-like operators. In this case,
an other deformation of su(2) appears in a natural way as a subalgebra and can
be interpreted as a deformation of the angular momentum algebra so(3). Its
representation is reducible and decomposes into irreducible ones that yields a
complete description of the same
On the uniformly continuity of the solution map for two dimensional wave maps
The aim of this paper is to analyse the properties of the solution map to the Cauchy problem for the wave map equation with a source term, when the target is the hyperboloid that is embedded in . The initial data are in . We prove that the solution map is not uniformly continuous
Sliderule-like property of Wigner's little groups and cyclic S-matrices for multilayer optics
It is noted that two-by-two S-matrices in multilayer optics can be
represented by the Sp(2) group whose algebraic property is the same as the
group of Lorentz transformations applicable to two space-like and one time-like
dimensions. It is noted also that Wigner's little groups have a sliderule-like
property which allows us to perform multiplications by additions. It is shown
that these two mathematical properties lead to a cyclic representation of the
S-matrix for multilayer optics, as in the case of ABCD matrices for laser
cavities. It is therefore possible to write the N-layer S-matrix as a
multiplication of the N single-layer S-matrices resulting in the same
mathematical expression with one of the parameters multiplied by N. In
addition, it is noted, as in the case of lens optics, multilayer optics can
serve as an analogue computer for the contraction of Wigner's little groups for
internal space-time symmetries of relativistic particles.Comment: RevTex 13 pages, Secs. IV and V revised and expande
14 challenges for conducting social neuroscience and longitudinal EEG research with infants
The use of electroencephalography (EEG) to study infant brain development is a growing trend. In addition to classical longitudinal designs that study the development of the neural, cognitive and behavioural function, new areas of EEG application are emerging, such as novel social neuroscience paradigms using dual infant-adult EEG recordings. However, most of the experimental designs, analysis methods, as well as EEG hardware were originally developed for single-person adult research. When applied to the study of infant development, adult-based solutions often pose unique problems that may go unrecognised. Here, we identify 14 challenges that infant EEG researchers may encounter when designing new experiments, collecting data, and conducting data analysis. Challenges related to the experimental design are: (1) small sample size and data attrition, and (2) varying arousal in younger infants. Challenges related to data acquisition are: (3) determining the optimal location for reference and ground electrodes, (4) control of impedance when testing with the high-density sponge electrode nets, (5) poor fit of standard EEG caps to the varying infant head shapes, and (6) ensuring a high degree of temporal synchronisation between amplifiers and recording devices during dual-EEG acquisition. Challenges related to the analysis of longitudinal and social neuroscience datasets are: (7) developmental changes in head anatomy, (8) prevalence and diversity of infant myogenic artefacts, (9) a lack of stereotypical topography of eye movements needed for the ICA-based data cleaning, (10) and relatively high inter-individual variability of EEG responses in younger cohorts. Additional challenges for the analysis of dual EEG data are: (11) developmental shifts in canonical EEG rhythms and difficulties in differentiating true inter-personal synchrony from spurious synchrony due to (12) common intrinsic properties of the signal and (13) shared external perturbation. Finally, (14) there is a lack of test-retest reliability studies of infant EEG. We describe each
of these challenges and suggest possible solutions. While we focus specifically on the social neuroscience and longitudinal research, many of the issues we raise are relevant for all fields of infant EEG research
Foreign Cultures, Sarbanes-Oxley Act and Cross-Delisting
Using a sample of foreign firms delisting shares from the United States over the period 2000 and 2004, this paper studies the impact of Sarbanes-Oxley Act (SOX) on the cross-delisting behavior of foreign firms based on the firm characteristics, legal tradition, overall culture and degree of individualism of the country of domicile. Pre-SOX, the propensity to delist is lower for firms from countries with cultural similarities to the U.S. and higher for firms from individualistic societies. Post-SOX these trends are reversed. Consistent with the existing research we find that the delisting decision of foreign firms cross- listed in the U.S. is based on the potential gains from listing based on the growth opportunities, length of presence in the U.S. and legal regulations of the country of domicile
- …